Dental instruments

ABSTRACT

A dental instrument having a unitary handle which includes a pair of elongated spaced apart arcuate grip portions. The grip portions are integrally connected to each other at a forward part of the handle and connected together at their rear ends by an integral rear part which extends transversely between the grips. A captive operating nut supported on the rear part is threadably engaged with an operating rod which extends longitudinally of the handle between and in spaced relation to the grips. The nut is operable to move an associated beak generally toward another opposing beak mounted in fixed position at the forward end of the handle. The movable beak may be pivotally supported on the forward part of the handle or may comprise a part of the operating rod.

BACKGROUND OF THE INVENTION

This invention relates in general to dental instruments and deals moreparticularly with improved instruments of the type used in theextraction of teeth.

When a conventional dental forceps is used to extract a tooth the dentalsurgeon must apply considerable holding force to the forceps whilesimultaneously applying extracting force to the instrument. Any slippingor loosening of the grip on the tooth may cause the crown of the toothto be broken off at or near the gum line, requiring surgical removal ofthe remaining portion of the tooth below the gum line. Excessive gumdamage may also result. Premature release of the tooth after extractionmay result in the tooth becoming lodged in the patient's esophagus ortrachea or in his sinus area. The risk of such premature release isparticularly severe when extraction is performed under generalanethesia.

In order to overcome the aforesaid problems, dental instruments havebeen provided which clampingly engage a tooth during extraction. Such aninstrument is shown and described in my U.S. Pat. No. 3,644,998 forDental Instrument, issued Feb. 29, 1972. The instrument of the aforesaidpatent has an elongated generally cylindrical handle which is rotatedabout its axis to effect clamping engagement of the beaks of theinstrument with a tooth. It is the general aim of the present inventionto provide improved clamping instruments of the aforedescribed generaltype.

SUMMARY OF THE INVENTION

In accordance with the invention a tooth extracting instrument includesan elongated handle which has a forward part and a pair of elongatedarcuate grips integrally connected at their forward ends to the forwardpart. The grips are bowed outwardly and are integrally connected inspaced relation at their rear ends by a rear part which extendstransversely between the rear ends of the grips. A first beak of theinstrument is supported in fixed position on the forward part of thehandle. A second beak is supported by the handle for movement generallytoward and away from the first beak. An operating means for moving thesecond beak generally toward and away from the first beak includes anelongated operating rod which extends longitudinally of the handle inspaced relation to the grips and which is supported by the forward partand the rear part for longitudinal sliding movement relative thereto.Manually operable means is provided for moving the operating rodrelative to the handle to move the first beak relative to the secondbeak and to maintain the beaks in selected position relative to eachother.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tooth extracting instrument embodyingthe present invention.

FIG. 2 is a somewhat enlarged fragmentary sectional view taken along theline 2--2 of FIG. 1.

FIG. 3 is a somewhat enlarged fragmentary sectional view taken along theline 3--3 of FIG. 1.

FIG. 4 is a somewhat enlarged fragmentary sectional view taken along theline 4--4 of FIG. 1.

FIG. 5 is a fragmentary sectional view taken along the line of 5--5 ofFIG. 1.

FIG. 6 is a somewhat enlarged fragmentary sectional view taken along theline 6--6 of FIG. 1.

FIG. 7 is a perspective view of another tooth extracting instrumentembodying the invention.

FIG. 8 is a somewhat enlarged fragmentary sectional view taken along theline 8--8 of FIG. 7.

FIG. 9 is a fragmentary sectional view taken along the line 9--9 of FIG.8.

FIG. 10 is a somewhat enlarged fragmentary sectional view taken alongthe line 10--10 of FIG. 7.

FIG. 11 is a sectional view taken generally along the line 11--11 ofFIG. 7.

FIG. 12 is a somewhat enlarged fragmentary longitudinal sectional viewthrough a portion of the instrument shown in FIG. 7.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Turning now to the drawings and referring first particularly to FIGS.1-6, a dental instrument embodying the present invention is indicatedgenerally by the reference numeral 10. The instrument 10 is particularlyadapted for use in the extraction of a tooth and generally comprises anelongated handle designated by the numeral 12 which has a forward part14. A pair of arcuately curved grips 16, 16 integrally connected to theforward part 14 extend rearwardly from it in spaced relation to eachother. The handle 12 further includes a rear part 18 which is integrallyconnected to the rear end portions of the grips 16, 16 and which extendstransversely between the grips. A rearwardly opening T slot 20 formed inthe rear part 18 extends transversely through it, as best shown in FIG.5.

The instrument 10 has a pair of beaks which includes a beak 22 supportedin fixed position on the forward part 14. Preferably, and as shown, thebeak 22 comprises an integral part of the handle 12 and projects in atransverse direction from the forward part 14. Another beak 24 issupported by the handle 12 for movement generally toward and away fromthe beak 22. Preferably, the beak 24 comprises an L-shaped end portionof an elongated operating rod 26 which extends longitudinally of thehandle 12 in spaced relation to the grips 16, 16. The beaks 22 and 24have opposing elongated recesses of arcuately contoured cross-section,as best shown in FIGS. 2 and 3, to conform generally to the anatomicalcontour of a tooth.

The operating rod 26 has a generally non-circular cross-section, atleast at its forward end, and is slidably received within a passageway28 which extends longitudinally through the forward part. The passagewayhas a non-circular cross-section which complements the cross-section ofan associated forward part of the operating rod 26. The rear portion ofthe operating rod 26 is externally threaded, extends through a centralopening in the rear part 18, and through and beyond the T slot 20, asbest shown in FIG. 5.

A captive cylindrical nut 30 threadably engaged with the rear endportion of the operating rod 26 has a cylindrical forward end portion 31of reduced diameter and generally T-shaped axial cross-section which isreceived within and retained by the T-slot 20. The peripheral surface ofthe nut 32 is preferably fluted, substantially as shown, to provide asubstantially nonslip gripping surface.

A stop pin 32 extends transversely through the operating rod 26 andprojects in opposite directions from it, substantially as shown in FIG.4. The stop pin is positioned to engage the forward part 14 near thejunction of the grips 16, 16 to limit forward travel of the operatingrod 14 and its associated integral beak 24. Engagement of the stop pin32 with the forward part 14 also serves to prevent disengagement of thenut 30 from the operating rod 26.

The non-traveling or captive nut 30 functions to move the beak 24generally toward and away from the beak 22 and into or out of clampingrelation with a tooth received therebetween. The unitary handle portiongives the instrument the "feel" of a conventional dental forceps andprovides spaced apart gripping surfaces which enable effective controlof the instrument without risk of slippage. The manually manipulatedcaptive nut 30 retains the beaks 22 and 24 in clamping engagement withthe tooth. Retention of the tooth by the beaks is not dependent uponforce exerted upon the handle grips.

Referring now to FIGS. 7-12, another dental instrument embodying thepresent invention is indicated generally by the reference numeral 10a.The instrument 10a is similar in many respects to the instrument 10,previously described, and parts which correspond to previously describedparts bear the same reference numerals and a letter "a" suffix and willnot be hereinafter further described in detail. The instrument 10adiffers from the instrument 10 primarily in the construction andarrangement of its beaks.

The illustrated instrument 10a is particularly adapted for use where aninstrument having beaks which extend in a longitudinal directionrelative to the axis of the instrument handle is required. Like theinstrument 10, the instrument 10a has a beak 22a which is supported infixed position on the forward part of the handle and which preferablycomprises an integral part of the handle 12a. However, the beak 22aextends in a longitudinal direction relative to the handle 12a. Theinstrument 10a also has another beak 24a which is pivotally mounted onthe forward part 14a by a pivot pin 34. The beaks 22a and 24a also havegenerally anatomically contoured arcuate tooth gripping surfaces, aspreviously described and as best shown in FIGS. 8 and 9 which illustratea typical beak of the instrument. The beak 24a has a generallyrearwardly facing cam surface 36 which is disposed rearwardly of thepivot pin 34 and which is inclined to the longitudinal axis of thehandle 12a, substantially shown in FIG. 12. A biasing spring 38,concealed within the forward part 14a and the beak 24a acts between themovable beak 24a and the forward part of the handle to bias the movablebeak to an open position away from the fixed beak 22a. The operating rod26a is generally similar to the operating rod 26, previously described,but differs therefrom in that it has a generally circular cross-sectionthroughout its length. The operating rod 26a also has a generallyforwardly facing cam surface 40 at its forward end, which is inclined tothe longitudinal axis of the operating rod, and a longitudinallyextending recess 42 which opens through one side of the rod. The forwardend portion of the operating rod 26a is slidably received within apassageway 28a which extends through the forward part 14a. The camsurface 40 is engageable with the cam surface 36 on the movable beak24a. A stop pin 32a mounted in the forward part 14a extends across thepassageway 28a and is engageable with abutment surfaces at opposite endsof the recess 42 to limit forward and rearward travel of the operatingrod 26a in response to rotation of a captive nut 30a. The stop pin 32aalso functions to prevent rotation of the operating rod about itslongitudinal axis and relative to the handle 12a.

The beaks 22a and 24a are normally biased toward an open position by thespring 38. Rotation of the operating nut 30a in one direction causescoengagement of the cam surfaces 36 and 40 to move the beak 24a towardthe beak 22a. The nut 30a cooperates with the operating rod 26a toreleasably retain the movable beak 24a in fixed position relative to thefixed beak 22a whereby to maintain the instrument in clamped engagementwith an associated tooth to be extracted.

I claim:
 1. A tooth extracting instrument comprising a longitudinallyextending unitary handle having a forward part and a pair of gripshaving forward end portions integrally connected in fixed relation toeach other and to said forward part and extending rearwardly from saidforward part in fixed spaced relation to each other, said handle havinga rear part integrally connected in fixed relation to and extendingtransversely between the rear ends of said grips, a first beak supportedin fixed position on said forward part, a second beak supported by saidhandle for movement generally toward and away from said first beak, andmeans for moving said second beak generally toward said first beak andincluding an elongated operating rod supported by said forward part andsaid rear part for longitudinal sliding movement relative to said handleand extending longitudinally of said handle between and in spacedrelation to said grips, said operating rod extending through said rearpart and having a rear portion extending rearwardly beyond said rearpart, and manually operable means engaged with said rear portion of saidoperating rod and supported by said rear part for moving said operatingrod relative to said handle, said manually operable means cooperatingwith said operating rod to maintain said first and second beaks inselected position relative to each other.
 2. A tooth extractinginstrument as set forth in claim 1 wherein each of said grips has afirst portion defining said forward end portion and integrally connectedto said forward part and curving transversely outwardly and rearwardlytherefrom and a second portion integrally connected to said firstportion and curving transversely inwardly and rearwardly therefrom andterminating at a junction with said rear part.
 3. A tooth extractinginstrument as set forth in either claim 1 or claim 2 wherein saidmanually operable means comprises a captive nut engaged in non-travelingrelation with said rear part and threadably engaged with said operatingrod.
 4. A tooth extracting instrument as set forth in claim 3 whereinsaid rear part has a T-shaped slot formed therein and said captive nutincludes a cylindrical portion having a T-shaped axial cross-sectionreceived within said T-shaped slot and retaining said nut innon-traveling engagement with said rear part.
 5. A tooth extractinginstrument as set forth in either claim 1 or claim 2 wherein said firstbeak is integrally connected to said forward part and projects in atransverse direction therefrom.
 6. A tooth extracting instrument as setforth in claim 5 wherein said second beak is integrally connected to theforward end portion of said operating rod.
 7. A tooth extractinginstrument as set forth in claim 6 wherein said second beak is generallyparallel to said first beak.
 8. A tooth extracting instrument as setforth in claim 1 or claim 2 wherein said second beak is supported forpivotal movement on said forward part and relative to said first beak.9. A tooth extracting instrument as set forth in claim 8 wherein saidmeans for moving said second beak comprises coengaging cam surfaces onsaid operating rod and said second beak.
 10. A tooth extractinginstrument as set forth in claim 9 including means for biasing saidsecond beak away from said first beak.
 11. A tooth extracting instrumentas set forth in claim 10 wherein said biasing means comprises a springacting between said second beak and said forward part.